Descriptions

OBJECTIVE: Our objective was to use episodic memory and executive function tests to determine whether or not Chiari
Malformation Type I (CM) patients experience cognitive dysfunction.
BACKGROUND: CM is a neurological syndrome in which the cerebellum descends into the cervical spine causing neural
compression, severe headaches, neck pain, and number of other physical symptoms. While primarily a disorder of the
cervico-medullary junction, both clinicians and researchers have suspected deficits in higher-level cognitive function.
DESIGN AND METHODS: We tested 24 CM patients who had undergone decompression neurosurgery and 24 age- and
education-matched controls on measures of immediate and delayed episodic memory, as well as three measures of
executive function.
RESULTS: The CM group showed performance decrements relative to the controls in response inhibition (Stroop
interference), working memory computational speed (Ospan), and processing speed (automated digit symbol substitution
task), but group differences in recall did not reach statistical significance. After statistical control for depression and anxiety
scores, the group effects for working memory and processing speed were eliminated, but not for response inhibition. This
response inhibition difference was not due to overall general slowing for the CM group, either, because when controls’ data
were transformed using the linear function fit to all of the reaction time tasks, the interaction with group remained
statistically significant. Furthermore, there was a multivariate group effect for all of the response time measures and
immediate and delayed recall after statistical control of depression and anxiety scores.
CONCLUSION: These results suggest that CM patients with decompression surgery exhibit cognitive dysfunction compared to
age- and education-matched controls. While some of these results may be related to anxiety and depression (likely proxies
for chronic pain), response inhibition effects, in particular, as well as a general cognitive deficit persisted even after control
for anxiety and decompression.